Ka-15
other
Ka-15

Ka-15. A photo. History. Characteristics.

 

In 1950 year OKB Kamov Engineers began working on a draft sketch of a ship helicopter with a crew of two people - Ka-15. The layout was standard: the crew in front, the engine behind. But due to the fact that the helicopter ship, it was necessary to make some amendments. Originally planned to install the engine AI-14V (take-off power 245 hp) and the main screws with trapezoidal blades made of wood material. They had to have a negative twist and a large constriction. The chord on the rotation axis in the theory was equal to 300 mm, and in the end it reached 100 mm. The filling factor of one of the three-bladed propellers was 3% and, naturally, each of 1%. In world practice, this was the lowest filling factor.

The development of a universal layout engineers engaged in VI Biryulin and BJ Kostin. Returning to the state tests, Nikolay Kamov chose one of the easiest options - conventional arrangement with wheel chassis. In the spring of the year 51 began designing this model, and on June 9 order came from the deputy PSM AN Bulganinova to start financing the Ka-15.

Ka-15

Project ship Ka-15 represented the compact size of the helicopter. The length has decreased in comparison with the Mi-1 twice, which in turn hampers the effective placement of all necessary in a helicopter to search for submarines. At first, about the buoyancy of the machine it was decided to forget. Installed four-wheel chassis.

Designed M. Kupfer wings had plywood paneling and foam-filled slots in the rear. This trick has been used to counter the blade flutter. If we take the example of the Mi-4, the vertical joints were installed friction dampers. Naturally, the column control system includes an intermediate polzushki. They solve the problem with common and differentiated steps.

The fuselage of the general design consisted of a duralumin frame, a power farm and a small tail boom. Washers, fastened stabilizer on the end of the beam, consisted of the steering and keel direction. The engine was located inside the fuselage along with the fan. In the gearbox of the motor there were planetary and conical lowering gears. Through it the power passed to a two-stage satellite distribution gearbox. A good view from the cockpit was ensured by the shape of the nose and glazing. The sliding doors made it possible to leave them in the open position, if necessary.

Ka-15

The first flight of the Ka-life tests performed in April 15 53 years. It raised to the sky Test Pilot DE Efremov. And in June the same year, the Minister of Aviation Industry Finance A. Khrunichev stopped shipments for this model. N. Kamov with great effort got a new, but smaller funding.

Certain structural parts have improved even during bench testing. For the first time the tension in the design particles tested in the factory tests. The overall results of voltage measurements give a chance to the high resources, but the overall refinement of the helicopter vibration issues lasted longer. This nuance in no way affected the successful completion of state tests (1995 year).

The problem remained with constant jolting. Gradually, with the use of new materials and methods of their application, ideas were developed to eliminate unnecessary vibrations. A huge contribution belongs to D. Efremov. In 56, it was decided to create a group to clarify and solve this problem. It included three cadre engineers: A. Ilyichenko, S. Gorshtein, F. Feldman. They studied the general concept of vibration and the way it appeared. In general, there were three reasons: self-oscillations, forced oscillations and flutter of blades. TsAGI employees also helped with the decision: I. Ananiev, A. Reznik, L. Popov, M. Galkin, and B. Zherebtsov.

The most vexing problem for the OP-3 was the presence of the longitudinal oscillations. OP-2 they are not particularly worried, because at this Ka-15 present rigidity in the upper screw and increase the shaft section. Frequency OP3 tests have shown that, due to a manufacturing defect the top support of a third-order practically absent.

Ka-15

These studies were carried out for several years, which in turn has allowed a lot of other problems. Increased take-out joint vertical type. Bronze bearings replaced by a needle. Between the rotor blades have built in the spring rods and set the Three-traction compound for the lower and upper swash. To increase the rigidity index supports the upper and lower screws raised shaft section and have built on top of a third support higher than the second on 360 mm. With these procedures became possible after the factory to start public testing of the helicopter.

But even when customers started to operate production models Ka-15, still had to resolve problems relating to vibration. For example, the flutter problem solved by means of a counterweight. On blades installed protivoflatternye outrigger loads.

Ka-15

In the future, another problem arose - the displacement of the blade-like centering back (the result of repair). Chinja blades, have closed up cracks in places of the trim tabs, bent to adjust the screws. At first they decided to sew them with a string of "mackey", but the military did not agree, and I had to replace the thread with a wire. The repairers slightly overdid during this operation, putting puttying more than necessary. Because of this, the center shifted backward. And this, in turn, led to inexplicable incidents. The first suspicion related to the flutter, but it was immediately discarded, since in the design bureau after the repair procedures of the blades all the machines were checked by a specialized technique.

After carrying out repairs, N. Kamov sent employees dealing with vibration problems to the locations of helicopter deployments. Each member of this group corrected the problems that appeared. A vivid example of the situation in Sevastopol. Test pilot A. Voronin during the flight found a very strong vibration at high speed. But the tape of the vibrator did not give any results. Starting at a speed of 140 km / h, there was a flutter and a violent shaking of the machine. The problem arose with the difference in distance between the screws. New indicators were introduced into the procedure for testing the possibility of flutter occurrence. Effective alignment should be one percent higher than the maximum speed in the absence of flutter signals. As a result, the adjustment became simpler.

Ka-15

The result of tests carried out repair and research procedures was an increase of performance in comparison with the expected. Ka-15 was able to carry a weight of 210 kg excluding own weight in 1410 kg. At the same time the engine power was 280 hp Same Mi Ka-1-15 conceded twice. Compact and aircraft handling machines allowed to land in confined areas.

After the start of serial Ka-15 in the bureau will continue to work to improve the characteristics, resources and opportunities for application of the helicopter. In 1957 year pilots Efremov D. and T. Rusia conducted a series of dangerous for health and life of a vortex ring research. Thanks to their courage were set the exact boundaries of the beginning of the regime and, most importantly, ways out of it.

In 57-m-15 helicopter UCA was created (instance of training) for training and training flights. It further flight instruments and curtains (for training flight blind) have been installed. There have also been set up different types of options for a helicopter to carry out agricultural activities (Ka-15M). This helicopter is equipped with various devices for the treatment of plants with chemical fertilizers. On the other helicopters were installed containers for postal delivery trucks and gondolas to transport sick or float landing gear.

Ka-15 characteristics:

Modification

  Ka-15

Diameter of the main rotor, m

  9.96

Length m

  6.26

Height, m

  3.35

Width, m

  2.85

Weight, kg

 

  empty

  968

  normal takeoff

  1360

  maximum take-off

  1460

engine's type

  1 PD AI-14B

power, kWt

  X 1 188

Maximum speed km / h

  155

Cruising speed, km / h

  120

Ferry range, km

  520

Practical range, km

  278

Practical ceiling, m

  3500

Static ceiling, m

  600

Crew

  1

Payload:

  1 passenger or 364 kg of cargo

 

 

Ka-15. Gallery.

Ka-15 schemeKa-15 block layoutKa-15 layout photo Side

Ka-15 with passengersKa-15 layoutKa-15 runway

Ka-15 before takeoffKa-15 in flightKa-15 photo Side

 

Helicopters

Blog and articles

upstairs